Hello, how can I remove artifacts in the shadow of an isosurface?
For exemple, I will compare the image of a sphere and the image of a sphere
created with isosurface.

This code give a good smoothed shadow :
camera {location <0,0,-4> look_at 0}
light_source {<-100,200,-100> color rgb 1}
sphere {0 1 pigment {rgb .9} }

But if I try the same with an isosurface, this code give artifacts :
camera {location <0,0,-4> look_at 0}
light_source {<-100,200,-100> color rgb 1}
isosurface {
 function{x*x+y*y+z*z-1}
 max_gradient 4
 contained_by{sphere{0,1.1}} open
 pigment {rgb .9}
}

Please see the pictures that illustrate this here :
http://quark67.free.fr/isosurface.html

Thanks for your help.
Sorry for bad english, this is not my first language.

Post a reply to this message

Wasn't it quark67 who wrote:
>Hello, how can I remove artifacts in the shadow of an isosurface?
>For exemple, I will compare the image of a sphere and the image of a sphere
>created with isosurface.
>
>This code give a good smoothed shadow :
>camera {location <0,0,-4> look_at 0}
>light_source {<-100,200,-100> color rgb 1}
>sphere {0 1 pigment {rgb .9} }
>
>But if I try the same with an isosurface, this code give artifacts :
>camera {location <0,0,-4> look_at 0}
>light_source {<-100,200,-100> color rgb 1}
>isosurface {
> function{x*x+y*y+z*z-1}
> max_gradient 4
> contained_by{sphere{0,1.1}} open
> pigment {rgb .9}
>}
>
>Please see the pictures that illustrate this here :
>http://quark67.free.fr/isosurface.html

You can decrease the accuracy. In this case try
        accuracy 0.00001
The downside is that as the accuracy gets smaller, the render time
increases.

-- 
Mike Williams
Gentleman of Leisure

Post a reply to this message

Mike Williams <nos### [at] econymdemoncouk> wrote:
> Wasn't it quark67 who wrote:

> >Please see the pictures that illustrate this here :
> >http://quark67.free.fr/isosurface.html
>
> You can decrease the accuracy. In this case try
>         accuracy 0.00001
> The downside is that as the accuracy gets smaller, the render time
> increases.
>
> --
> Mike Williams
> Gentleman of Leisure

Hello, you can see in the web page http://quark67.free.fr/isosurface.html what
an
accuracy 1e-6
get after "code 4" on the page (1e-6=0.000001).
This is not better :(

Post a reply to this message

Wasn't it quark67 who wrote:
>Mike Williams <nos### [at] econymdemoncouk> wrote:
>> Wasn't it quark67 who wrote:
>
>> >Please see the pictures that illustrate this here :
>> >http://quark67.free.fr/isosurface.html
>>
>> You can decrease the accuracy. In this case try
>>         accuracy 0.00001
>> The downside is that as the accuracy gets smaller, the render time
>> increases.
>>
>> --
>> Mike Williams
>> Gentleman of Leisure
>
>Hello, you can see in the web page http://quark67.free.fr/isosurface.html what
>an
>accuracy 1e-6
>get after "code 4" on the page (1e-6=0.000001).
>This is not better :(

It looks better than that for me. What anti-aliassing are you using?

-- 
Mike Williams
Gentleman of Leisure

Post a reply to this message

Mike Williams <nos### [at] econymdemoncouk> wrote:
>
> It looks better than that for me. What anti-aliassing are you using?
>
> --
> Mike Williams
> Gentleman of Leisure

Sampling Method : Adaptive
Threshold:0.3
Recursion depth:3
Jitter:1.0

Have you a different setting?
Can I see what you obtain please? (and your code and setting).
Thanks.

Ooops! I just read your mail adress and I see that I'm speak with the author of
a very good isosurface tutorial ;) Thanks for your work!

Post a reply to this message